Hyd Accumilator

[geneP]

One of the original questions was "What's it's purpose?" on a John Deere tractor. I don't know for sure, but after reviewing all the definitions of an accumulator, I'm guessing (if it is indeed an accumulator) that it is to smooth out the hydraulics operation. This is an industrial tractor, so the pump GPM is probably higher than a similar ordinary tractor. Let's assume that it has an open hydraulic system, so there is minimum pressure in the supply line from the pump while no functions are open. If you were using a FEL, for example, and had a relatively heavy load in the bucket and wanted to raise the load. When the "up" valve was opened the supply line pressure almost instantly increases to a point high enough to move the cylinders. My thought is that the accumulator in this case is used like a standpipe, and cushions the initial surge of pressure to minimize the shock at the bucket. Does this sound reasonable?

 

[Keoke]

Hi guys, to add just one more application for acumulators.
On some engines with tubro-chargers an acumulator is used to keep oil flowing to the tubro bearings after engine shutdown & peroids of low oil pressure. This technique keeps the static residual oil in the bearing housing from turning to coke and messing up the bearings on the next startup. There is a one-way check valve between the oil pump and the acumulator that prevents the oil from flowing back to the pump after shutdown. Depending on size of the acumulator, the idea is to keep fresh oil moving through the tubro bearings long enough for the tubro housing to cool down.
By the way, it's always a good idea to let a tubro engine idle a bit allowing the tubro to cool down before turning the engine off. This is especially true if the engine does not have an acumulator.

regards,
george,
keoke

 

[scruffy]

Keoke, interesting tidbit of info, but somehow, not one I think I will ever have to worry about. I just can't picture ever owning anything with a turbo charger on it...just ain't efficient in the direction I would like efficiency to take, plus the repair costs/parts are too high for the standard life span of such a system. To find an auto with factory turbo charging still in operation after 70,000 miles is rather rare from my past experience as a mechanic, and normal repair costs at that time was around a grand and up. Simplicity is hard to find now-a-days, but still my preferred way.

 

[Bird]

Scruffy, turbos are something I've never had, but have driven lots of equipment with them and read a lot about them. And I may be wrong, but from what I've read and been told, it seems that:
1. A turbo on a gasoline engine increases power and acceleration and decreases fuel mileage and engine life.
2. A turbo on a diesel engine increases both power and acceleration and fuel mileage without shortening engine life.
But of course, George is right about letting the turbo cool before shutting down.
Anyone disagree? And if so, why?

Bird

 

[scruffy]

Bird, I knew the disadvantages on the gas engines, but not the advantages on the diesels. Gotta be careful of those statements, or next thing we know, MarkC will have another improvement going! Now wouldn't that be something! A turbo-charged Kubota!

 

[Bird]

Re: <font color=blue>A turbo-charged Kubota!</font color=blue> I guess you know the M110 and M120 are turbo-charged diesels. And one neighbor has 3 John Deeres in that size range and they're all turbo-charged. And you know many buyers (especially RVers pulling travel trailers) were having aftermarket turbos put on their Ford diesel pickups before Ford made it standard equipment. But I do wonder why Mark hasn't added one to his L4310./w3tcompact/icons/wink.gif

Bird

 

[scruffy]

Bird I didn't know the big M's were or had Turbo available! Course, I have to deal in early 70 reality for the old L175, I know, I know, its really an L1500 but that's ONE reality I don't want to face up to.
As for the RV'rs, I know, I installed a few myself, as well as tuned headers, etc. The gas rigs even had cams/lifters /turbos and tuned exhaust setup kits for them. Just depended on the $ factor.
To drift back to the hydraulics for a moment, why can't small hydraulic cylinders be added to the scarifiers for adjustment control? Other than the dollar factor that is.

 

[Roy]

Like Bird said, there are companies which currently manufacturer after market turbo conversion kits for some truck engines (like Advanced Turbo Systems, Inc), and there are after market manufactures which make propane charger system kits (like Bully Dog Technologies). So, who knows, in the near future we may be able to add-on the turbo and propane. Then we can forget the Ag/Bar/Turf tire decision… go with the slicks /w3tcompact/icons/smile.gif.

Spoke too soon…. After I posted, I found a UK company that does make turbo conversion kits for tractors (although, larger than most of ours): www.tb-turbo.co.uk. So, maybe that day is not too far off.

 

[TomG]

I saw a used box scraper advertised on the web that did have hydraulic scarifiers. I think it was an IH unit. I talked to the dealer who said that the scarifiers were continuously adjustable.

 

[TomG]

I've heard comments saying a cool-down is good. I recall the comments as being about engines rather than turbos, and I thought a cool down was for the engine. Guess it could be for both, and as far as I know cool-downs are good.